Interlaboratory Method Validation for Determination of Polysorbate 80 for Analysis of mAbs

Polysorbate 80 (PS80) is a widely used surfactant in therapeutic monoclonal antibodies (mAbs) because it prevents mAb aggregation and stabilizes the drug product. Various analytical methods have been published and are available for measuring PS80, each with its own limitations. In this study, an HPLC method employing an evaporative light scattering detector (ELSD) was developed for multiproduct analysis of PS80. Method validation was conducted across multiple laboratories using different types of instruments and ELSD detectors. The method was validated using various immunoglobulin G (IgG) mAb molecules and different sources of PS80, with the results showing that it can accurately measure PS80 concentrations ranging from 0.05 to 0.5 mg/mL. Robustness tests demonstrated that the method tolerates up to 160 mg/mL mAb interference, through either sample dilution or protein precipitation. This method can be recommended as a release/quality control method for PS80 concentration determination in therapeutic mAbs.